D. Fedorenko - Academia.edu (original) (raw)
Papers by D. Fedorenko
Springer Proceedings in Physics, 2013
Contents Structure of Cadmium Alkanoate Glasses. Spectral Properties of Nanocomposites: nanoc... more Contents Structure of Cadmium Alkanoate Glasses. Spectral Properties of Nanocomposites: nanocrystals CdSe in the metal alkanoate matrix. Experimental Techniques for Measure Nonlinear Optical Constants: Z-scan and SBF; Z-scan under CW Diode laser and Model of photoinduced lens; Measurement of Nonlinear Refractive Index n 2. Measurement of Nonlinear Absorption Coefficient ᵦ. Conclusions.
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 1999
The accuracy of the Content should not be relied upon and should be independently verified with p... more The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden.
Journal of Molecular Liquids
Abstract Spectral properties and the nonlinear optical response in nanocomposites of ionic liquid... more Abstract Spectral properties and the nonlinear optical response in nanocomposites of ionic liquid crystals (ILC) of cadmium octanoate containing hybrid core/shell nanoparticles (NPs) is studied. The hybrid NPs consist of either an Ag-core and a semiconductor-shell, or a semiconductor1-core and a semiconductor2-shell. Two-wave mixing with excitation by nanosecond pulses laser was used to observe the generation of high diffraction orders in the dynamic regime. The coefficients of optical nonlinear refraction were determined based on the measured diffraction efficiencies. Excitation of polaritons in the hybrid NPs and their electronic type of nonlinearity are responsible for the photoinduced nonlinear response in these nanocomposites.
Molecular Crystals and Liquid Crystals, 2002
We studied the thermal optical nonlinearity in a suspension of ultra-fine absorbing particles in ... more We studied the thermal optical nonlinearity in a suspension of ultra-fine absorbing particles in a nematic liquid crystal. Each particle "works" as a light-controlled "heater" of surrounding LC that results in change of the refractive index of the suspension. If the distance between absorbing particles in the suspension is less than the characteristic length of thermodiffusion, the thermal and refractive
Ukrainian Journal of Physics, 2015
Proceedings of SPIE, 2005
ABSTRACT
Optics and Photonics News, 2013
2013 International Conference on Advanced Optoelectronics and Lasers (CAOL 2013), 2013
ABSTRACT The absorption and photoluminescence spectra of semiconductor CdS and CdSe nanoparticles... more ABSTRACT The absorption and photoluminescence spectra of semiconductor CdS and CdSe nanoparticles (NPs) in cadmium alkanoates anisotropic glasses have been studied. NPs are chemically synthesized in thermotropic ionic liquid crystalline (TILC) smectic A phase of cadmium alkanoates which are used as nanoreactors. The glassy nanocomposites are obtained by rapid cooling the TILC to room temperature. In the new cadmium alkanoates matrices, the CdS and CdSe NPs have a small dispersion of their sizes, their shape is nearly spherical, they are stable over time, and they are ordered in glassy smectic A matrix. The thermo-optical nonlinearity of the cadmium octanoate nanocomposites contained CdSe NPs is characterized by extremely large values of the nonlinear refractive index, n2, under relatively low-powered laser pulses.
OPTIKA '98: 5th Congress on Modern Optics, 1998
ABSTRACT
Nanoscale Research Letters, 2015
Dielectric properties of ionic composites consisted of cadmium octanoate matrix and semiconductor... more Dielectric properties of ionic composites consisted of cadmium octanoate matrix and semiconductor or metal nanoparticles have been investigated. The nanoparticles of different nature (semiconductor CdS, metal Au, and metal core-semiconductor shell Au-CdS) were chemically synthesized in the smectic A phase of (Cd +2 (C 7 H 15 COO) −2 , CdC 8 ) that was used as a nanoreactor. These nanocomposites are very stable and well ordered; the size and shape of the nanoparticles (NPs) are well controlled during the synthesis. The main aim of the research was to examine the influence of nanoparticles on the dielectric properties of ionic matrix, which has smectic A ordered structure. Electrical characteristics were investigated at different temperatures, which correspond to different phases of the material. The conductivity of nanocomposites has an activation nature. The electrical conductivity anisotropy confirms the structural anisotropy of the nanocomposites. The conductivity of the nanocomposite along the cation-anion layers is higher by 2 orders of magnitude than that across the cation-anion layers. Basing on the experimental data, we proposed the simple model of the charge carriage process.
Molecular Crystals and Liquid Crystals, 2007
We report an experimental study of light-induced anchoring evolution of azo-dye-doped liquid crys... more We report an experimental study of light-induced anchoring evolution of azo-dye-doped liquid crystal (LC) in nematic phase and present a model of this effect. To describe the experimental results we considered the gliding effect as a result of light-induced anisotropic adsorption=desorption of dye molecules on=from the boundary polymer aligning layer in the presence of light-induced bulk torque due to ordering of absorbing dye molecules. Our model qualitatively describes the observed drift of the light-induced easy axis.
Physical Review E, 2001
We found the effect of a hidden photoalignment of a dye-doped nematic liquid crystal ͑LC͒ on a no... more We found the effect of a hidden photoalignment of a dye-doped nematic liquid crystal ͑LC͒ on a nonphotosensitive polymer surface after polarized irradiation of the cell in the isotropic phase. We observed that irradiation resulted in a uniform planar orientation of the LC after cooling to the mesophase. The direction of a light-induced easy axis on the polymer can be either parallel or perpendicular to the polarization of the incident light, depending on the light intensity. We attribute this behavior to two mechanisms of photoalignment: light-induced adsorption of dye molecules on the substrate, and anisotropic desorption in a previously adsorbed dye layer. The experimental results on photoalignment of a LC on a thin dye film confirm our model.
Springer Proceedings in Physics, 2013
Contents Structure of Cadmium Alkanoate Glasses. Spectral Properties of Nanocomposites: nanoc... more Contents Structure of Cadmium Alkanoate Glasses. Spectral Properties of Nanocomposites: nanocrystals CdSe in the metal alkanoate matrix. Experimental Techniques for Measure Nonlinear Optical Constants: Z-scan and SBF; Z-scan under CW Diode laser and Model of photoinduced lens; Measurement of Nonlinear Refractive Index n 2. Measurement of Nonlinear Absorption Coefficient ᵦ. Conclusions.
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 1999
The accuracy of the Content should not be relied upon and should be independently verified with p... more The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden.
Journal of Molecular Liquids
Abstract Spectral properties and the nonlinear optical response in nanocomposites of ionic liquid... more Abstract Spectral properties and the nonlinear optical response in nanocomposites of ionic liquid crystals (ILC) of cadmium octanoate containing hybrid core/shell nanoparticles (NPs) is studied. The hybrid NPs consist of either an Ag-core and a semiconductor-shell, or a semiconductor1-core and a semiconductor2-shell. Two-wave mixing with excitation by nanosecond pulses laser was used to observe the generation of high diffraction orders in the dynamic regime. The coefficients of optical nonlinear refraction were determined based on the measured diffraction efficiencies. Excitation of polaritons in the hybrid NPs and their electronic type of nonlinearity are responsible for the photoinduced nonlinear response in these nanocomposites.
Molecular Crystals and Liquid Crystals, 2002
We studied the thermal optical nonlinearity in a suspension of ultra-fine absorbing particles in ... more We studied the thermal optical nonlinearity in a suspension of ultra-fine absorbing particles in a nematic liquid crystal. Each particle "works" as a light-controlled "heater" of surrounding LC that results in change of the refractive index of the suspension. If the distance between absorbing particles in the suspension is less than the characteristic length of thermodiffusion, the thermal and refractive
Ukrainian Journal of Physics, 2015
Proceedings of SPIE, 2005
ABSTRACT
Optics and Photonics News, 2013
2013 International Conference on Advanced Optoelectronics and Lasers (CAOL 2013), 2013
ABSTRACT The absorption and photoluminescence spectra of semiconductor CdS and CdSe nanoparticles... more ABSTRACT The absorption and photoluminescence spectra of semiconductor CdS and CdSe nanoparticles (NPs) in cadmium alkanoates anisotropic glasses have been studied. NPs are chemically synthesized in thermotropic ionic liquid crystalline (TILC) smectic A phase of cadmium alkanoates which are used as nanoreactors. The glassy nanocomposites are obtained by rapid cooling the TILC to room temperature. In the new cadmium alkanoates matrices, the CdS and CdSe NPs have a small dispersion of their sizes, their shape is nearly spherical, they are stable over time, and they are ordered in glassy smectic A matrix. The thermo-optical nonlinearity of the cadmium octanoate nanocomposites contained CdSe NPs is characterized by extremely large values of the nonlinear refractive index, n2, under relatively low-powered laser pulses.
OPTIKA '98: 5th Congress on Modern Optics, 1998
ABSTRACT
Nanoscale Research Letters, 2015
Dielectric properties of ionic composites consisted of cadmium octanoate matrix and semiconductor... more Dielectric properties of ionic composites consisted of cadmium octanoate matrix and semiconductor or metal nanoparticles have been investigated. The nanoparticles of different nature (semiconductor CdS, metal Au, and metal core-semiconductor shell Au-CdS) were chemically synthesized in the smectic A phase of (Cd +2 (C 7 H 15 COO) −2 , CdC 8 ) that was used as a nanoreactor. These nanocomposites are very stable and well ordered; the size and shape of the nanoparticles (NPs) are well controlled during the synthesis. The main aim of the research was to examine the influence of nanoparticles on the dielectric properties of ionic matrix, which has smectic A ordered structure. Electrical characteristics were investigated at different temperatures, which correspond to different phases of the material. The conductivity of nanocomposites has an activation nature. The electrical conductivity anisotropy confirms the structural anisotropy of the nanocomposites. The conductivity of the nanocomposite along the cation-anion layers is higher by 2 orders of magnitude than that across the cation-anion layers. Basing on the experimental data, we proposed the simple model of the charge carriage process.
Molecular Crystals and Liquid Crystals, 2007
We report an experimental study of light-induced anchoring evolution of azo-dye-doped liquid crys... more We report an experimental study of light-induced anchoring evolution of azo-dye-doped liquid crystal (LC) in nematic phase and present a model of this effect. To describe the experimental results we considered the gliding effect as a result of light-induced anisotropic adsorption=desorption of dye molecules on=from the boundary polymer aligning layer in the presence of light-induced bulk torque due to ordering of absorbing dye molecules. Our model qualitatively describes the observed drift of the light-induced easy axis.
Physical Review E, 2001
We found the effect of a hidden photoalignment of a dye-doped nematic liquid crystal ͑LC͒ on a no... more We found the effect of a hidden photoalignment of a dye-doped nematic liquid crystal ͑LC͒ on a nonphotosensitive polymer surface after polarized irradiation of the cell in the isotropic phase. We observed that irradiation resulted in a uniform planar orientation of the LC after cooling to the mesophase. The direction of a light-induced easy axis on the polymer can be either parallel or perpendicular to the polarization of the incident light, depending on the light intensity. We attribute this behavior to two mechanisms of photoalignment: light-induced adsorption of dye molecules on the substrate, and anisotropic desorption in a previously adsorbed dye layer. The experimental results on photoalignment of a LC on a thin dye film confirm our model.